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Bacterial chemotactic oligopeptides and the intestinal mucosal barrier

Journal Article · · Gastroenterology; (United States)
OSTI ID:5722129

Intestinal absorption and enterohepatic circulation of N-formyl-methionyl-leucyl-/sup 125/I-tyrosine, a bioactive synthetic analog of the bacterial chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine has been investigated in the rat. In ileum and proximal and distal colon, dithiothreitol, which increases mucosal permeability, increased peptide absorption and biliary recovery fourfold, 70-fold, and 20-fold over control values, respectively. When dithiothreitol was combined with d-l-benzyl succinate, a potent inhibitor of intestinal carboxypeptidase, absorption and biliary recovery from ileal loops increased markedly to 40-fold over control, whereas there was no further increase in absorption from colon loops. There was a strong correlation between biliary N-formyl-methionyl-leucyl-/sup 125/I-tyrosine recovery and intestinal absorption of /sup 51/Cr-ethylenediaminetetraacetate, a marker of passive mucosal permeability (r = 0.97). We conclude that in the ileum both enzymic degradation and restricted mucosal permeability contribute to the intestinal barrier to luminal bacterial formyl oligopeptides. In the colon, however, enzymic mechanisms are less active and restricted mucosal permeability is the major factor. Abnormalities of the intestinal mucosal barrier to proinflammatory bacterial peptides could play a role in inflammatory disorders of the gut.

Research Organization:
Univ. of Otago Medical School, Dunedin (New Zealand)
OSTI ID:
5722129
Journal Information:
Gastroenterology; (United States), Journal Name: Gastroenterology; (United States) Vol. 97:1; ISSN GASTA
Country of Publication:
United States
Language:
English